[RFC]: add `lapack/base/dlange`

### Description

This RFC proposes to add `lapack/base/dlange`

### Related Issues

_No response_

### Questions

_No response_

### Other

_No response_

### Checklist

- [x] I have read and understood the [Code of Conduct](https://github.com/stdlib-js/stdlib/blob/develop/CODE_OF_CONDUCT.md).
- [x] Searched for existing issues and pull requests.
- [x] The issue name begins with `RFC:`.

Begin with the proposed lapack/base/dlange entry point. The RFC does not specify implementation details, tests, or acceptance criteria, so clarify the expected scope and definition of done with maintainers before coding.

Written by the indexing model from the issue text.